Medtronc Evolut TAVR
Medtronic Evolut TAVR. [Image from Medtronic]

Medtronic (NYSE:MDT) announced data from multiple trials supporting its transcatheter heart valve replacement devices.

Data were presented at the 34th Transcatheter Cardiovascular Therapeutics (TCT) conference in Boston. Results covered the company’s self-expanding transcatheter aortic valve replacement (TAVR) devices and its transapical transcatheter mitral valve replacement (TMVR) system.

Medtronic kicked off TCT by announcing the full U.S. launch of its next-generation Evolut FX TAVR system.

Examining HALT in Medtronic CoreValve and Evolut program

The Pathological Study of Hypo-Attenuated Leaflet Thickening (HALT) represents part of the CoreValve and Evolut program. It compares microCT and histology findings of valve leaflet thickening. Medtronic said in a news release that the trial is the first to compare such things. It may provide clinical insights into the long-term durability of transcatheter aortic valves (TAVs) and treatment of HALT.

Medtronic’s study evaluated the extent of pathologic changes of valve thrombosis, neointimal thickening, inflammation, and calcification over time in 110 TAVs explanted at surgery or autopsy. Explanted valves were collected from 11 clinical studies, including more than 7,500 participants. It also evaluated areas of leaflet thickening through microCT and histology to assess prevalence, length and underlying cellular composition for these areas.

Study outcomes

The study found that approximately 45% of leaflets in explanted valves showed at least some degree of leaflet thickening. The prevalence registered as comparable with the microCT and histology assessment. Histological scores by implant duration showed no change in thrombus and inflammation scores over time.

Neointima, structural changes, and calcification scores increased with greater implant duration. Thrombi begin organizing after 30 days and by one year had a more organized morphology that may be resistant to treatment.

“As TAVR continues to grow as a treatment option for aortic stenosis, identifying pathological changes to TAVs over time is critical for understanding their long-term durability,” said Nina Goodheart, SVP and president of the Structural Heart & Aortic business at Medtronic. “Today’s results offer additional clinical evidence for our CoreValve Evolut Program to better understand the importance of early treatment when HALT is detected.”

Data supports TMVR system for treating mitral regurgitation (MR)

Medtronic also presented results from the Intrepid pilot study and Intrepid early feasibility study. Data offers new insights supporting transapical and transfemoral approaches using the Intrepid TMVR system to treat mitral regurgitation (MR), Medtronic said.

Intrepid integrates self-expanding, dual-stent technology with a tissue valve. It is delivered through a catheter and placed directly into the native mitral valve. Medtronic designed it to restore normal blood flow through the heart without the need for open-heart surgery.

“With the Intrepid TMVR system, our goal is to ultimately offer viable alternative options for patients who are considered inoperable for surgical mitral regurgitation replacement,” said Goodheart. “The data presented at TCT builds on initial results from the Intrepid TMVR pilot study and is another step forward in our mission to provide safe and effective delivery options for patients with mitral valve disease.”

The pilot study assessed safety and performance of Intrepid TMVR using a transapical delivery. Results demonstrated positive outcomes at three years. Echocardiographic outcomes showed stable valve function with low mean mitral valve gradients.

Results demonstrated persistent MR reduction with less than 98% of patients with paravalvular leak. The study also showed significant reduction in left ventricular end-diastolic volume.

Early feasibility results come in positive, too

Thirty-day outcomes — and the first one-year results for 14 patients — demonstrated successful device implantation and valve performance.

Intrepid produced high rates of implantation at 96.7%. Device safety included acceptable rates of periprocedural complications (27%) and no mortality or stroke.

Medtronic also reported excellent valve performance including near complete elimination of MR in all patients (91%). It also improved symptoms and quality of life.

“We are encouraged by these early results for the Intrepid TMVR system using the novel transfemoral and look forward to evaluating and furthering evidence around the clinical outcomes and hemodynamics of the device,” said Dr. Firas Zahr, interventional cardiologist and co-director of the Complex Heart Valve Program at Oregon Health & Science University and principal investigator. “These results can help to establish TMVR as a safe treatment option for patients that are high-risk for conventional surgical approaches.”